If you run tests on your site with tools such as Google’s web.dev, you may have seen recommendations that you offer the ‘HTTPS/2 protocol’, a fairly technical but fundamental piece of backstage web technology. I won’t even attempt to go into it here, but if you want a nice explanation of HTTPS/2 with a decent real-world analogy, there’s one here. It’s enough to know that you should have moved on to this, and you can check that your site has done so here.
Being on HTTP/2 will not provide your website with a search engine ranking boost in itself, but the advantages it gives are all things which really do make a difference in SEO, namely faster loading, reduced data transfer, better user experience and increased security, which is really what it’s all about. Some older articles may suggest that Google isn’t using HTTP/2 in its web crawling, but that’s changed; it is now crawling over half of URLs using HTTP/2.
Unlike the change from HTTP to HTTPS a few years back, HTTP/2 does not require changes in URLs or anything complex; if your server is able to support HTTP/2, it may automatically serve content over the new protocol. Otherwise, it could be worth talking to your hosting service.